If you are looking for a high grade the question that will make or break you will be your worst, not the ones you know well. Choosing that question correctly can make all the difference. The time constraints within an exam make the choice of question more important still. You don't have time to start another if you make the wrong choice!

So how do you choose and how do you tackle those questions?

First, scan through the paper, quickly recognising the questions you know you can answer well. There will usually be one or two that you feel less confident about.

Leave these aside for now, and assuming you have divided up your time properly and left enough for these questions, get started on your good ones. This will get you into a state of 'flow' and increase your confidence. Don't dwell on the problems. When you have finished your good questions, feeling more confident and having some of your exam behind you already, take a look again at the ones you are not sure about. They will need a little more attention than the good ones when you scan through them.

Check through each section and note the parts you do know and the parts you don't know or are unsure of. Try to allocate rough marks to these areas. Sometimes they may be on the exam paper itself. If not, use your knowledge of marking schemes in your exam preparation to estimate marks. Do a rough calculation for each question you are considering.

The choice may be obvious at this point if one stands out from the others. If they are still close in marks, then choose one anyway, but start, if it makes sense for your subject, with the difficult part at the end. Don't start with the parts you know. If you find the difficult part is worse than you thought then you will have minimised the time lost on that question and will have some time to change to the other question. If you had started from the beginning and then realised your mistake, then the damage would be worse.

It is preferable to choose the right one the first time of course, but using this technique you can at least reduce the pressure in choosing your question which in itself can impair your judgement, knowing that the lost time will be minimal.

Make sure you practice this technique on old exam papers before the exam and finish both your worst questions to see if you made the right choice. It will make a good content revision exercise at the same time, so hopefully there will be no bad questions come exam time!